Spiderman, Superman, and Batman may still wear the tights in the world of comics, but for rebellious artists like Bill Sienkiewicz, who are itchy to redefine the medium, these heroes have lost their allure. Luckily there are other big fish in the sea — Moby Dick, for instance, which Sienkiewicz (in collaboration with writer Dan Chichester) has adapted for the recently resuscitated Classics Illustrated series.

Now a joint venture between First Publishing and the Berkley Publishing Group, Classics Illustrated arrived in bookstores last month, after a 19-year absence, with three new adaptations in addition to Moby Dick: Gahan Wilson’s version of Poe’s ”The Raven,” Rick Geary’s impression of Dickens’ Great Expectations, and Kyle Baker’s take on Lewis Carroll’s Through the Looking-Glass. All four have a look and tone very much in keeping with the ”graphic novels” that revolutionized comic books during the ’80s. And though they may not outsell more traditional comics, they are providing some talented artists with unusual outlets for their mutinous ways.

But why would a Caped Crusader-crazed kid from northern New Jersey snub the superheroes who so vividly colored his childhood? Why desert them for political issues, social concerns, and — sufferin’ succotash! — Herman Melviile? For the 31-year-old Sienkiewicz, the defection process began 11 years ago, ironically, when he walked smugly into the Manhattan offices of Marvel Comics, flashed his muscle-bound portfolio, and was hired faster than you can say onomatopoeia.

Winning a dream job just like that may be right up there with leaping tall buildings at a single bound. But in retrospect, the artist, who cites his current influences as David Lynch, Francis Bacon, and Gustav Klimt, sees the experience as a cautionary tale about ” ‘being careful what you wish for because you just might get it.’ ”

By the time Sienkiewicz began drawing Marvel’s Fantastic Four in 1980, his job had become ”just another job. I had gotten married around that time, and it was like, ‘Let’s see: Two more Fantastic Fours and we can buy a lamp.’ That was about as exciting as it got.”

It became increasingly obvious that even though Sienkiewicz had grown up on superheroes, he didn’t want to grow old with them. So he decided to diversify. Four years ago, he took an extended leave from capes, cowls, and secret identities — and he’s never looked back.

In the last year alone, besides Moby Dick, Sienkiewicz has feverishly devoted his time to such unlikely comic-book projects as Strip AIDS, U.S.A., an anthology of AIDS-related cartoons; Brought to Light, a two-part ”graphic docudrama” about the Iran-contra scandal; and Stray Toasters, an eerie, nonlinear tale involving some hellacious household appliances.

Sienkiewicz realizes that of all his work, Moby Dick is the book most likely to fall into the hands of non-comic-book readers. But students who plan to pick up Sienkiewicz’s version (rather than Melville’s) to prep themselves for next week’s pop quiz may well find the comic book almost as ponderous as its source. ”And that is exactly the point,” Sienkiewicz says, ”to show them that a comic book isn’t necessarily what they expect it to be.”

Stripped of the traditional comic-book panels, word balloons, and flat, color-by-numbers artwork, Sienkiewicz’s perfect-bound Moby Dick is a highly stylized, hauntingly painted interpretation. Images overlap and collide, and shards of text are scattered across every page in a style the artist describes as ”impressionistic, expressionistic an attempt to delve into as many layers of the story as we could.”

Though Sienkiewicz is the first to admit that a 44-page distillation of Moby Dick is hardly a substitute for the novel, he does feel that it is ”a worthwhile introduction” to the source, as well as a further validation of the comic book as a respectable art form — superheroes notwithstanding.

”More than anything,” he says, ”the superheroes have perpetuated this perception of the medium as being just for children. But that’s like saying, ‘There are only these kinds of movies’ or ‘There are only those kinds of movies,’ and then along comes Citizen Kane. To me, the comic-book medium is a way of using words and pictures together to say more than either the words or the pictures alone.”

Although he doesn’t rule out the possibility of returning to superheroes somewhere down the road, Sienkiewicz says, ”Right now, I’m more drawn to political causes, to stories about how human beings interact in a social context. For me, the medium seems to work best when it’s most subversive.”

The artist’s next project, due in March, is Big Numbers, a 45-character, 480-page comic-book series about a small town in England that becomes the site of an American-style shopping mall. The story was written by Alan Moore, creator of DC Comics’ successful Watchmen series (1986), and Sienkiewicz says that his visuals will incorporate photographs, warped photocopy images, and three-dimensional objects. (In Stray Toasters, light switches and pieces from old television sets were among the found objects pasted directly onto the art boards.)

The subject matter of Big Numbers seems as out of place in a comic book as AIDS, Iran-contra, and Moby Dick, which may explain why Sienkiewicz found it so irresistible. ”Look at it this way,” the artist suggests. ”If someone told you that you had to spend the rest of your life making hamburgers, wouldn’t you at least go out of your way to make them interesting hamburgers?”